BACKGROUND OF THE INVENTION
[0001] The present invention relates to lubricating devices. More particularly, it relates
to lubricating devices which are capable of dispensing very accurate quantities of
special lubricants at very low flow rates for lubricating tools and work pieces during
machining operations.
SUMMARY OF THE INVENTION
[0002] As is known, during machining operations large amounts of heat are generated by the
friction between the tool and work piece. If not effectively dealt with, this heat
is highly undesirable since it leads to the early dulling or failure of the tool;
or it may render the tool inoperable in other ways, such as by welding to it chips
of metal formed during the machining operations.
[0003] One conventional way of solving the problem of excessive heat buildup during machining
operations is to apply special lubricants to the tool and work piece which are so
effective at reducing the friction between the tool and work piece that the heat generated
during machining operations is reduced to acceptable levels. Said special lubricants
are applied at very low flow rates to the tool and work piece; and are essentially
consumed during the machining operations.
[0004] Some examples of said special lubricants are Boelube brand lubricant and Accu-Lube
brand lubricant; both of which are liquids at room temperature. Boelube comprises
high carbon (long carbon chain) fatty alcohols and is manufactured by the Orelube
Corporation located in Plain View, New York. Accu-Lube comprises fractions of fatty
acids and fatty alcohols, and is sold by Lubricating Systems, Inc. of Kent, Washington.
[0005] Although the exact flow rates of said special lubricants will vary somewhat depending
on the particular special lubricant being used, on the particular machining operation
being conducted, on the hardness and metal from which the work piece is made, on the
particular machine tool being used, etc., typically such flow rates will be in the
range of from about 0.10 to about 10.0 cc's (cubic centimeters) per minute.
[0006] However, the use of such very low flow rates of said special lubricants does present
several problems. For example, since said special lubricants are typically very expensive,
it will be appreciated that if the flow rate of said special lubricants is higher
than is required for effective machining operations, costly wastage will occur. On
the other hand, if the flow rate is too low, loss of the tool, and possibly the work
piece, may result. Accordingly, extremely precise metering of such very low flow rates
is imperative.
[0007] In addition, since the exact flow rates of said special lubricants which are needed
will vary according to the particular special lubricant being used, the particular
machining operations being performed, the particular machine tool being used, the
hardness and type of the metal from which the work piece is made, etc., it is essential
that it be possible to achieve very small changes in the already very low basic flow
rate of said special lubricants which is consistent with superior tool life and operation.
[0008] Further, it is necessary that the lubricating apparatus which delivers such very
low flow rates of said special lubricants be highly reliable. This is because if it
fails to continuously deliver the precise flow rate of said special lubricants which
is required, loss of the tool, and possibly the work piece, will occur shortly after
the flow of said special lubricants is too low or is interrupted.
[0009] Accordingly, one of the objects of the present invention is to provide a highly reliable,
precision, very low flow rate lubricator for machining operations. Another object
of the present invention is to provide such a lubricator which has the further capability
of having its flow rates selectively adjustable in minute amounts for the optimum
minimum delivery of said special lubricants to the tool and work piece.
[0010] In basic form, the lubricator of the present invention comprises a precision, positive
displacement, pneumatic injection pump which delivers an output pulse of lubricant
to a lubricant output tube in response to each input air pulse which is delivered
to it. The lubricant output tube is adapted to convey the lubricant output pulses
to the machine tool where they are then applied to the tool and work piece by any
suitable conventional means.
[0011] The lubricator of the present invention may be provided with two internal check valves.
One check valve achieves one of the objects of the present invention, which is to
prevent back flow of lubricant from the lubricator into the lubricator's source of
lubricant during the pumping stroke of the lubricator's piston. The other check valve
achieves another of the objects of the present invention, which is to prevent back
flow of lubricant from the lubricator's lubricant output tube into the lubricator
during the return stroke of the lubricator's piston.
[0012] The lubricator of the present invention may also be provided an adjustable stop which
controls the travel of the lubricator's piston, and which thus controls the amount
of lubricant pumped by each pumping stroke of the piston. Preferably, the adjustable
stop is provided with positive stops for its minimum and maximum adjustments, which
achieves another of the objects of the present invention, namely, to prevent the user
from endlessly turning the adjustable stop in either direction with no further actual
adjustment in amount of lubricant pumped by the piston.
[0013] Since many machine tools incorporate a pneumatic chip blower and may use compressed
air to apply said special lubricants to the tool and work piece, a further object
of the present invention is to conveniently supply both said special lubricants and
compressed air to the machine tools. To this end, the lubricator of the present invention
may be internally arranged so that its lubricant output tube and its atomizing air
output hose are coaxially arranged, with its lubricant output tube running inside
of its atomizing air output hose.
[0014] In addition, the lubricator may include needle valve means for selectively varying
the amount of atomizing air which it delivers to its atomizing air output hose. Naturally,
if only lubricant is needed by a particular machine tool, the flow of compressed air
from the lubricator can be cut off by using the lubricator's needle valve means or
by cutting off the lubricator's source of compressed air. Similarly, if only compressed
air is needed by a particular machine tool, the flow of lubricant from the lubricator
can be cut off by using the adjustable stop for the lubricator's piston, by cutting
off the lubricator's source of input air pulses, or by cutting off the lubricator's
source of lubricant.
[0015] A further object of the present invention is to provide a lubricator which can simultaneously
supply lubricant and compressed air to more than one machine tool; with the amount
of lubricant and compressed air being supplied to each machine tool being independently
controllable. This object is achieved by providing the lubricator with stackable valve
bodies; with each valve body being used to supply lubricant and atomizing air to its
respective machine tool. The valve bodies are constructed so that the lubricator's
input lubricant, input air pulses and input compressed air are shared by all of the
valve bodies; whose air relief means are in fluid communication with each other.
[0016] It should be understood that the foregoing is intended to be a brief, not an exhaustive,
summary of the objects, features, advantages and characteristics of the present invention,
since these and further objects, features, advantages and characteristics of the present
invention will be directly or inherently disclosed to those skilled in the art to
which it pertains by the following, more detailed description of the present invention.
BRIEF DESCRIPTION OF THE FIGURES
[0017]
Fig. 1 is a partially exploded, perspective view of the present invention;
Fig. 2 is a bottom plan view of the invention's upper plate;
Fig. 3 is a bottom plan view of the invention's lower plate;
Fig. 4 is a top plan view of the invention's valve body;
Fig. 5 is a bottom plan view of the invention's valve body;
Fig. 6 is a partial cross-sectional view taken generally along line 6-6 of Fig. 1,
with some parts shown in elevation;
Fig. 7 is a partial cross-sectional view taken generally along line 7-7 of Fig. 6,
with some parts shown in elevation; and
Fig. 8 is a cross-sectional view taken generally along line 8-8 of Fig. 6, with some
parts shown in elevation.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
CONSTRUCTION OF THE INVENTION
[0018] Turning now to Fig. 1, the lubricator of the present invention is shown generally
designated at 10. In basic form, lubricator 10 comprises an upper plate 12, a valve
body 14 and a lower plate 16 which are assembled together with a pair of assembly
bolts 18. Bolts 18 pass through bolt holes 20, 22 in upper plate 12 and valve body
14, respectively, and are screwed into threaded bores 24 in lower plate 16. Upper
and lower plates 12, 16 and valve body 14 can be made from any strong, crack resistant
metal or plastic. Due to its complexity, valve body 14 is preferably injection molded
from plastic or die cast from metal in order to help minimize its cost.
[0019] As seen in Figs. 1 and 2, upper plate 12 includes a threaded lubricant input bore
25, which is adapted to be connected by any conventional means to a source of lubricant.
Each of upper plate 12's bolt holes 20 is sized to receive the head of its respective
bolt 18 within it; and includes an internal shoulder 27 (see Fig. 2), which acts as
a stop for its respective bolt 18 when the bolt's head is flush with upper plate 12's
top surface.
[0020] Referring now to Figs. 1 and 3, it is seen that lower plate 16 has a threaded atomizing
air input bore 26 with an O-ring recess 28 for O-ring 30; a threaded piston air pulse
input bore 32 with an O-ring recess 34 for O-ring 36; a threaded piston air relief
bore 38 with an O-ring recess 40 for O-ring 42; and a blind bore 44 which forms an
O-ring recess for O-ring 46. Rubber O-rings 30, 36, 42 and 46 form seals between corresponding
portions of the top of base plate 16 and the bottom of valve body 14.
[0021] Lower plate 16's threaded atomizing air input bore 26 is adapted to be connected
by any conventional means to a compressed air source. The pressure of the compressed
air delivered to lubricator 10 from the compressed air source will be selected by
the particular user in accordance with his needs and the particular machine tool being
used. However, typically, a machine tool's chip blower and lubricant atomizer or applicator
use compressed air having pressure of about 80 pounds per square inch (psi).
[0022] Lower plate 16's threaded air pulse input bore 32 is adapted to connected to any
conventional source of pulses of compressed air, such as an air logic device made
by Crouzet Division Aerospatial, 62-64 Emile Zola Avenue, Paris, France 75115 under
part number 81 532 001 for the air logic device's base, and part number 81 506 820
for the air logic device's main body. Said air logic device is designed to operate
with an input air pressure of 42 to 120 psi and will, in response to its input air,
deliver output pulses of compressed air with an air pulse frequency which is selectively
adjustable from 0 to 180 air pulses per minute. Because said air logic device will
generate its output air pulses with an input air pressure of 42 to 120 psi, the device
is relatively immune to the changes in air pressure typically encountered in a manufacturing
facility's installed compressed air system, thus enhancing the reliability of lubricator
10.
[0023] Lower plate 16's threaded piston air relief bore 38 can either communicate directly
with the atmosphere, or, if desired, it can be connected to any conventional conduit
means so that it communicates with the atmosphere at a location which is remote from
lubricator 10.
[0024] The top of lower plate 16 has a peripheral locating shoulder 48 which mates with
a corresponding peripheral locating recess 50 (see Fig. 5) in the bottom of valve
body 14, for accurate registration of lower plate 16 and valve body 14 with respect
to each other when lubricator 10 is assembled.
[0025] Referring now to Figs. 1 and 4, it is seen that valve body 14 includes a vertical
atomizing air input bore 52 with an O-ring recess 54 for O-ring 56; a vertical lubricant
input bore 58 with an O-ring recess 60 for O-ring 62; a vertical piston air relief
bore 64 with an O-ring recess 66 for O-ring 68; and a vertical piston air pulse input
bore 70 with an O-ring recess 72 for O-ring 74. Rubber O-rings 56, 62, 68, 74 form
seals between corresponding portions of the top of valve body 14 and the flat, smooth
bottom of upper plate 12. The top of valve body 14 includes a locating shoulder 76
whose purpose will be described below. When lubricator 10 is assembled, there is fluid
communication between valve body 14's bore 58 and upper plate 12's bore 25. When lubricator
10 is assembled, upper plate 12's smooth, flat bottom surface acts as a plug for the
upper ends of valve body 14's bores 52, 64, 70. Alternatively, an air relief bore
could be provided in upper plate 12 which was in fluid communication with valve body
14's vertical piston air relief bore 64.
[0026] Referring now to Fig. 5, it is seen that the bottoms of the valve body 14's atomizing
air input bore 52, lubricant input bore 58, piston air relief bore 64 and piston air
pulse input bore 70 are each provided with a flat O-ring seal surface 77 for their
respective O-rings 30, 46, 42 and 36. When lubricator 10 is assembled, there is fluid
communication between valve body 14's bores 52, 64, 70 and lower plate 16's bores
26, 38, 32, respectively; while lower plate 16's blind bore 44 acts to plug the lower
end of valve body 14's bore 58.
[0027] Alternatively, when lubricator 10 has only one valve body 14, upper and lower plates
12, 16 could be eliminated. In such an event, one end of valve body 14's bores 52,
58, 64, 70 would be plugged by any suitable conventional means; and other end of valve
body 14's bores 52, 58, 64, 70 would be connected by any suitable conventional means
to a compressed air source, to a lubricant source, to the atmosphere, and to an input
air pulse source, respectively.
[0028] Naturally, upper plate 12's lubricant input bore 25 and lower plate 16's blind bore
44 could be interchanged. Similarly, one or more of lower plate 16's bore's 26, 38,
32 could be located in upper plate 12; and for each bore which was so located in upper
plate 12, lower plate 16 would be modified to act as a plug for valve body 14's corresponding
bore 52, 64, 70, respectively.
[0029] As was mentioned above, in basic form, lubricator 10 comprises an upper plate 12,
a valve body 14 and a lower plate 16, all of which are assembled together with a pair
of bolts 18. However, it is within the scope of the present invention for two or more
valve bodies 14 to be used, with the valve bodies 14 being stacked on top of each
other between upper and lower plates 12, 16. For example, if two valve bodies 14 were
used, then the peripheral locating shoulder 76 in the top of the lower valve body
14 would be fitted into the peripheral locating recess 50 in the bottom of the upper
valve body 14 for accurate registration of the two valve bodies 14 with respect to
each other. As many valve bodies 14 can be stacked on top of each other between upper
and lower plates 12, 16 as is desired.
[0030] If two or more valve bodies 14 are used, each lower valve body 14 is provided with
a set of O-rings 56, 62, 68, 74 to provide a seal between its bores 52, 58, 64, 70
and the corresponding bores 52, 58, 64, 70 in the adjacent valve body 14 above it.
In addition, assembly bolts 18 would be selected to have a length sufficient to hold
top plate 12, valve bodies 14 and bottom plate 16 assembled together. If two or more
valve bodies 14 are used, there is fluid communication between their respective bores
52, 58, 64, 70.
[0031] Turning now to Fig. 6, it is seen that a horizontal, longitudinal main bore 78 extends
the complete length of valve body 14. The right hand portion of main bore 78 defines
a lubricant pumping chamber 102, a piston air relief chamber 104 and a piston air
pulse input chamber 106. Air relief chamber 104 is in fluid communication with vertical
piston air relief bore 64; and air pulse input chamber 106 is in fluid communication
with vertical air pulse input bore 70.
[0032] As seen in Figs. 1 and 6, the right hand portion of main bore 78 carries a piston
assembly 80 and a stop assembly 82.
[0033] Piston assembly 80 comprises a piston return spring 84, a piston lubricant seal (a
rubber O-ring) 86, a brass piston 88 and a rubber piston air seal 90. As seen in Figs.
1 and 6, piston 88 is a one-piece member comprising, from left to right, a piston
shaft 92 having an annular recess 94 for lubricant seal 86; an annular shoulder 96;
and a piston head 98 having an annular recess 100 for piston air seal 90. Piston lubricant
seal 86 and piston air seal 90 are assembled to piston 88 by passing them over piston
shaft 92 and piston head 98, respectively, until they are seated in their respective
annular recesses 94, 100.
[0034] As seen in Fig. 6, piston return spring 84 is located in piston air relief chamber
104. Alternatively, piston return spring 84 could be suitably sized to fit inside,
and could be located inside, lubricant pumping chamber 104.
[0035] Referring again to Figs. 1 and 6, it is seen that stop assembly 82 comprises an adjustable
brass stop 110, a stop seal (a rubber O-ring) 112, and a brass stop nut 114. Stop
110 is a one-piece member comprising, from left to right, a stop shaft 118 which butts
against piston 88's head 98; an annular should 120; a neck 122 having an annular recess
124 for stop seal 112; and a threaded head 126 which screws into stop nut 114. Stop
seal 112 is assembled to stop 110 by passing it over stop neck 122 until it is seated
in its annular recess 124. Stop 110 and stop nut 114 are assembled together by screwing
stop 110's threaded head 126 into stop nut 114.
[0036] In order to assemble valve body 14, piston assembly 80, and stop assembly 82 together,
piston spring 84 is first inserted over piston 88's shaft 92 until it butts against
piston shoulder 96. Then piston 88 (with its lubricant seal 86, air seal 90 and spring
84) is inserted into main bore 78 until it is positioned as seen in Fig. 6. Last,
stop nut 114 (with its stop 110 and stop seal 112) is screwed all of the way into
the right hand end of main bore 78 until it makes sealing contact with valve body
14's annular ridge seal 122, as is also seen in Fig. 6.
[0037] Referring now to Figs. 6 and 8, a horizontal, transverse lubricant input bore 128
provides fluid communication between vertical lubricant input bore 58 and main bore
78. Lubricant input bore 128 includes an enlarged portion in which is located a conventional
lubricant input check valve comprising check ball 130 and check spring 132. After
check ball 130 and check spring 132 are inserted into transverse lubricant input bore
128, they are held in place by plug 134 which is secured in lubricant input bore 128
by any conventional means, such as by gluing or by a tight, leak proof friction fit.
Alternatively, a conventional check valve, which served the same purpose as said lubricant
input check valve, could be located outside of lubricator 10 between the lubricant
source and upper plate 12's lubricant input bore 25.
[0038] Referring now to Figs. 1 and 6, it is seen that the left hand portion of main bore
78 carries an atomizing air/lubricant output assembly 136. Atomizing air/lubricant
output assembly 136 comprises an atomizing air output hose 138, a lubricant output
tube 140, a barb fitting 142, a lubricant output seal 144, and a conventional lubricant
output check valve comprising a lubricant output check spring 146 and a lubricant
output check ball 148. Alternatively, a conventional check valve, which served the
same purpose as said lubricant output check valve, could be located outside of lubricator
10 in or at the end of its lubricant output tube 140.
[0039] In order to assemble valve body 14 and atomizing air/lubricant output assembly 136
together, lubricant output check ball 148 and lubricant output check spring 146 are
first inserted into main bore 78 until they are located as seen in Fig. 6. Next, rubber
of soft plastic lubricant output seal 144 is inserted into main bore 78 until it is
located as seen in Fig. 6, where it is held in place by a snug, leak proof friction
fit. Then lubricant output tube 140 is inserted into lubricant output seal 144, as
seen, where it is held in place by a snug, leak proof friction fit. Next, barb fitting
142 is passed over lubricant output tube 140 and is then screwed into the left end
of horizontal, transverse bore 78 until it makes sealing contact with valve body 14's
ridge seal 150, as seen. Barb fitting 142's threads are straight rather than tapered,
in order to help prevent valve body 14 from being split when barb fitting 142 is screwed
into it. A seal between barb fitting 142 and valve body 14 is provided by valve body
14's ridge seal 150, rather than by any tapering of barb fitting 142's threads. Last,
atomizing air output hose 138 is passed over lubricant output tube 140, and is then
passed over and secured to barb fitting 142 as seen.
[0040] As best seen in Figs. 6 and 7, the left hand portion of main bore 78 defines an atomizing
air chamber 153; and as best seen in Figs. 1, 6 and 7, valve body 14 defines a transverse,
horizontal atomizing air bore 152 which is in fluid communication with vertical atomizing
air input bore 52 and atomizing air chamber 153. The internal diameter of the bore
in barb fitting 142 is sized considerably larger than the outside diameter of lubricant
output tube 140; in order to permit the free flow of atomizing air from atomizing
air chamber 153 to atomizing air output hose 138 through barb fitting 142.
[0041] Referring now to Figs. 1 and 7, atomizing air chamber 153 carries an atomizing air
needle valve assembly 154 which comprises a brass needle valve nut 156, a brass needle
158 and a needle valve seal (a rubber O-ring) 160. Needle valve assembly 154 is generally
of conventional construction.
[0042] Needle 158 has an annular recess 162 for needle valve seal 160, and has a threaded
head 164. Needle valve seal 160 is assembled to needle 158 by passing it over needle
158 until it is seated in its needle valve recess 162. Needle 158 is assembled to
needle nut 156 by screwing its head 164 into needle nut 156. Valve body 14 and needle
valve assembly 154 are then assembled together by screwing needle nut 156 (with its
needle 158 and needle valve seal 160) into atomizing air chamber 152 until it makes
sealing contact with valve body 14's ridge seal 166, as seen.
OPERATION OF THE INVENTION
[0043] Before lubricator 10 is ready for operation, certain connections need to be made.
[0044] A source of lubricant is connected to top plate 12's threaded lubricant input bore
25. Since lubricant input bore 25 is in fluid communication with the vertical lubricant
input bore 58 of each valve body 14, input lubricant is thereby provided to each valve
body 14.
[0045] A source of compressed air pulses is connected to bottom plate 16's threaded air
pulse input bore 32. Since air pulse input bore 32 is in fluid communication with
the vertical air pulse input bore 70 in each valve body 14, compressed air pulses
are thereby provided to each valve body 14.
[0046] Bottom plate 16's threaded piston air relief bore 38 may be permitted to vent directly
to the atmosphere; or if remote venting is desired, an air relief line may be connected
to bottom plate 16's threaded piston air relief bore 38. Since piston air relief bore
38 is in fluid communication with each vertical piston air relief bore 64 in each
valve body 14, piston air relief is thereby provided for each valve body 14.
[0047] A source of pressurized atomizing air is connected to bottom plate 16's threaded
atomizing air input bore 26. Since atomizing air input bore 26 is in fluid communication
with the vertical atomizing air input bore 52 in each valve body 14, atomizing air
is thereby provided for each valve body 14.
[0048] Once the above connections have been made, lubricator 10 is then primed by allowing
it to run for a short time until air bubble free lubricant flows out of the free end
of lubricant output tube 140. Once lubricator 10 has been primed, its operation is
as follows.
[0049] Referring now to Fig. 6, upon the delivery of a compressed air pulse to valve body
14's air pulse input chamber 106 from the source of pressurized air pulses via air
pulse input bore 70, the compressed air pulse acts on piston air seal 90 and piston
head 98. This forces piston 88 to move to the left and compress piston return spring
84. As piston 88 moves to the left, it forces lubricant out of lubricant pumping chamber
102, thereby forcing check ball 148 to open and permit lubricant to be forced through
lubricant output tube 140. While this is happening, back flow of lubricant from the
central portion of main bore 78 into vertical lubricant input bore 58 through horizontal
transverse lubricant input bore 128 is prevented by check ball 130 and check spring
132, as best seen in Fig. 8. As piston 88 is being forced to the left by the input
air pulse, the air in air relief chamber 104 which is compressed by piston 88 exits
chamber 104 through vertical piston air relief bore 64, to vent, directly or indirectly,
to the atmosphere.
[0050] When the input air pulse is over, piston return spring 84 forces piston 88 to move
to the right to its starting position. As piston 88 starts to move to the right, check
spring 146 forces check ball 148 closed, thereby preventing any back flow of lubricant
from lubricant output tube 140 into main bore 78 of valve body 14. As piston 88 is
moving to the right, a negative pressure is formed in lubricant pumping chamber 102
which immediately sucks check ball 130 open, thereby permitting lubricant from vertical
lubricant input bore 58 to be sucked into lubricant pumping chamber 102 through transverse
lubricant input bore 128. As piston 88 is moving to the right, a negative air pressure
is formed in air relief chamber 104, thereby sucking air into chamber 104 from vertical
piston air relief bore 64. As piston 88 is moving to the right, it also compresses
the air in air pulse input chamber 106 and forces it out of chamber 106 through vertical
air pulse input bore 70. The source of compressed air pulses which is connected to
vertical air pulse input bore 70 is preferably constructed so that, between delivering
air pulses to input bore 70, it vents to the atmosphere the air which is forced out
of chamber 106 by piston 88.
[0051] The amount of lubricant which is pumped by each pumping stroke of piston 88 is governed
by how far piston 88 travels in response to each input air pulse. In turn, the amount
of travel of piston 88 is governed by the adjustment of stop 110.
[0052] Referring now to Fig. 6, as stop 110's threaded head 126 is screwed clockwise, the
left end of stop 110's shaft 118, which butts against piston 88's head 98, forces
piston 88 to the left. As stop 110's threaded head 126 is screwed clockwise further
and further, the left end of piston 88's shoulder 96 will eventually be forced into
contact with piston stop shoulder 108 of main bore 78. This results in zero travel
of piston 88 and no lubricant being pumping by piston 88. Thus, piston stop shoulder
108 acts, in effect, as a fixed positive stop for the clockwise adjustment of stop
110; meaning that it acts as a fixed positive stop for the lower pumping limit for
each pumping stroke of piston 88, which is zero.
[0053] If stop 110's threaded head 126 is then screwed counterclockwise, the travel of piston
88 is thereby permitted to increase in direct proportion to how far threaded heat
126 is screwed counterclockwise. Thus, the amount of lubricant pumped by each pumping
stroke of piston 88 is also thereby permitted to increase in direct proportion to
how far threaded head 126 is screwed counterclockwise. As stop 110's threaded head
126 is screwed counterclockwise more and more, further movement of stop 110 will eventually
be prevented when its shoulder 120 contacts the left end of stop nut 114. Thus, stop
nut 114 acts as a fixed positive stop for the counterclockwise adjustment of stop
110; meaning that it acts as a fixed positive stop for the upper pumping limit of
each pumping stroke of piston 88.
[0054] Thus, it is seen that the adjustment by stop 110 of both the upper and lower pumping
limits for each pumping stroke of piston 88 is subject to positive stops. This is
desirable since it prevents the possibility that stop 110 could be turned endlessly
in either direction without any actual adjustment of the amount of lubricant being
pumped by lubricator 10.
[0055] As was discussed above, the exact flow rates of said special lubricants which the
user will require lubricator 10 to deliver to the tool and work piece will vary according
to the particular special lubricant being used, the particular machining operation
being formed, the particular machine tool being used, the hardness and type of the
metal from which the work piece is made, etc. However, lubricator 10 will typically
be required to provide substantially continuous flow rates of said special lubricants
in the range of from about 0.10 to about 10.0 cc's per minute. Although, as mentioned
above, the source of compressed air pulses can provide 0 to 180 compressed air pulses
per minute; it is preferred that it be adjusted to deliver from about 20 to about
60 compressed air pulses per minute, so that lubricator 10 will deliver lubricant
substantially continuously to its lubricant output tube 140.
[0056] When the typical flow rates of lubricant and preferred number of air pulses per minute
which were mentioned above are used, the amount of lubricant which lubricator 10 will
deliver to its lubricant output tube 140 for each pumping stroke of its piston 88,
will range from about 0.0017 cc's to about 0.17 cc's per minute. It is preferred that
pumping chamber 102, piston assembly 80 and stop assembly 82 be sized and arranged
so that the amount of lubricant pumped by each pumping stroke of piston 88 can be
varied by as little as about 0.0001 cc, or less. It is also preferred that lubricator
10 provide lubricant to lubricant output tube 140 at pressures of up to about 10,000
psi. This is done by suitably selecting the pressure of the input compressed air pulses,
and by suitably selecting the size of lubricator 10's pumping chamber 102 and piston
assembly 80. The valve body 14 illustrated in the figures is about four inches long,
about 1 and 1/2 inches wide and about 1 and 1/4 inches thick; with its various components
being sized accordingly.
[0057] Turning now to Figs. 6 and 8, the rate of flow of atomizing air from vertical atomizing
air input bore 52 through horizontal atomizing air bore 152 to atomizing air chamber
153 and atomizing air output hose 138 is governed by needle valve assembly 154. If
threaded needle valve head 164 is screwed clockwise as far as it will go, then the
left end of needle 158 will plug horizontal atomizing air bore 152, thereby cutting
off the flow of atomizing air to atomizing air chamber 153 and atomizing air output
hose 138. If threaded needle valve head 164 is then screwed counterclockwise, the
rate of flow of atomizing air through horizontal atomizing air bore 152 to atomizing
air chamber 153 and atomizing air output hose 138 is thereby permitted to increase
in direct proportion to how far threaded needle valve head 164 is screwed counterclockwise.
Although the pressure and rate of flow of the atomizing air delivered by lubricator
10 to atomizing air output hose 138 will depend upon the needs of the user, typically
the atomizing air will be delivered by lubricator 10 at pressures of about 80 psi
and at flow rates of up to about 3 to 4 cubic feet per minute (cfm). Since the pressure
of the atomizing air which is delivered by lubricator 10 is essentially the same as
the pressure of the input compressed air which is provided to lubricator 10, it is
apparent that by suitably selecting the pressure of the input compressed air to lubricator
10 the user can control the pressure of the atomizing air which is delivered by lubricator
10. If a greater flow rate of atomizing air is needed, then the size of all of the
components through which the atomizing air passes in lubricator 10 can be increased
accordingly.
[0058] In view of the foregoing, these and further modifications, adaptations and variations
of the present invention will now be apparent to those skilled in the art to which
it pertains, within the scope of the following claims. It is understood that the foregoing
forms of the invention were described and/or illustrated strictly by way of non-limiting
example.
1. A precision, positive displacement, very low flow rate, pneumatic lubricator for
a tool and work piece; wherein said lubricator is adapted to be connected to an air
pulse source which generates a stream of successive input air pulses; wherein said
lubricator is also adapted to be connected to a lubricant source which supplies lubricant;
wherein said lubricator comprises a valve body; wherein said valve body defines a
main bore comprising an air pulse chamber, a piston chamber and a lubricant pumping
chamber; wherein said valve body comprises:
an air pulse input means for receiving said input air pulses and for delivering said
input air pulses to said valve body's air pulse chamber; a lubricant input means for
receiving said lubricant and for delivering said lubricant to said valve body's lubricant
pumping chamber; a piston means for pumping said lubricant; wherein said piston means
is located in said piston chamber at least substantially between said air pulse chamber
and said lubricant pumping chamber; wherein, when an input air pulse is received by
said air pulse chamber during use, said input air pulse forces said piston means to
move from a starting position towards said lubricant pumping chamber to pump at least
some of said lubricant out of said lubricant pumping chamber; an output means for
receiving said lubricant which is pumped out of said lubricant pumping chamber by
said piston means; and a piston return means for returning said piston means to its
said starting position between successive said input air pulses.
2. The lubricator according to claim 1, wherein said valve body further comprises:
a first check valve means for preventing back flow of said lubricant from said lubricant
pumping chamber into said lubricant input means while said piston means pumps at least
some of said lubricant out of said lubricant pumping chamber; wherein said first check
valve means is also for permitting said lubricant to flow from said lubricant input
means into said lubricant pumping chamber while said piston means returns to its said
starting position; and a second check valve means for preventing back flow of said
lubricant from said output means into said lubricant pumping chamber while said piston
means is returning to its said starting position; wherein said second checks valve
means is also for permitting said lubricant to flow from said lubricant pumping chamber
into said output means while said piston means pumps at least some of said lubricant
out of said lubricant pumping chamber.
3. The lubricator according to claim 1, wherein said valve body further comprises
adjustable stop means for selectively adjusting the travel of said piston means; and
wherein said travel of said piston means governs the quantity of said lubricant which
is pumped by said piston means in response to each said input air pulse.
4. The lubricator according to claim 3, wherein said piston means has predetermined
minimum and maximum travel limits; and wherein said valve body further comprises minimum
and maximum positive stop means for preventing further adjustment of said adjustable
stop means when said piston means reaches its said predetermined minimum and maximum
travel limits, respectively.
5. The lubricator according to claim 1, wherein said lubricator is further adapted
to be connected to a compressed air source which supplies compressed air; and wherein
said valve body further comprises a compressed air input means for receiving said
compressed air and for delivering it to said valve body's output means.
6. The lubricator according to claim 5, wherein said compressed air input means further
comprises needle valve means for selectively controlling the amount of said compressed
air which flows from said compressed air input means to said output means.
7. The lubricator according to claim 5, wherein said output means comprises a lubricant
output line which receives said lubricant which is pumped out of said lubricant pumping
chamber; wherein said output means further comprises a compressed air output line
which receives said compressed air from said needle valve means; and wherein said
output lines are arranged coaxially with respect to each other.
8. The lubricator according to claim 1, wherein said piston return means comprises
a spring located in a spring portion of said piston chamber; and wherein said valve
body further comprises air relief means for providing air relief for said spring portion
of said piston chamber.
9. The lubricator according to claim 1,
wherein said lubricator further comprises a top plate, a bottom plate and an assembly
means; wherein said assembly means are for holding said top plate, said valve body
and said bottom plate in a predetermined relationship with respect to each other,
with said valve body sandwiched between said top and bottom plates;
wherein one of said top and bottom plates defines an air pulse bore which receives
said input air pulses from said air pulse source and delivers them to said valve body's
air pulse input means; wherein the other of said top and bottom plates comprises a
plug for an adjacent end of said valve body's air pulse input means;
wherein one of said top and bottom plates defines a lubricant bore which receives
said lubricant from said lubricant source and delivers it to said valve body's lubricant
input means; and wherein the other of said top and bottom plates comprises a plug
for an adjacent end of said valve body's lubricant input means.
10. The lubricator according to claim 9, wherein said lubricator is further adapted
to be connected to a compressed air source which supplies compressed air; wherein
said valve body further comprises a compressed air input means for receiving said
compressed air and for delivering it to said valve body's output means; wherein one
of said top and bottom plates defines a compressed air bore which receives said compressed
air from said compressed air source and delivers it to said valve body's compressed
air input means; and wherein the other of said top and bottom plates comprises a plug
for an adjacent end of said valve body's compressed air input means.
11. The lubricator according to claim 9, wherein said piston return means comprises
a spring located in a spring portion of said piston chamber; wherein said valve body
further comprises air relief means for providing air relief for said spring portion
of said piston chamber; and wherein at least one of said top and bottom plates defines
an air relief bore which is in fluid communication with said valve body's air relief
means.
12. The lubricator according to claim 1, wherein said lubricator further comprises
a top plate, a bottom plate and an assembly means; wherein there are at least two
of said valve bodies; wherein said assembly means are for holding said top plate,
said valve bodies and said bottom plate in a predetermined relationship with respect
to each other, with said valve bodies sandwiched on top of each other between said
top and bottom plates; wherein all of said valve bodies' air pulse input means are
in fluid communication with each other; wherein all of said valve bodies' lubricant
input means are in fluid communication with each other; wherein said top plate and
said bottom plate each have a respective adjacent one of said valve bodies;
wherein one of said top and bottom plates defines an air pulse bore which receives
said input air pulses from said air pulse source and delivers them to said air pulse
input means of its said respective adjacent one of said valve bodies; wherein the
other of said top and bottom plates comprises a plug for an adjacent end of said air
pulse input means of its said respective adjacent one of said valve bodies;
wherein one of said top and bottom plates defines a lubricant bore which receives
lubricant from said lubricant source and delivers it to said lubricant input means
of its said respective adjacent one of said valve bodies; and wherein the other of
said top and bottom plates comprises a plug for an adjacent end of said lubricant
input means of its said respective adjacent one of said valve bodies.
13. The lubricator according to claim 12, wherein said lubricator is further adapted
to be connected to a compressed air source which supplies compressed air; wherein
each said valve body further comprises a compressed air input means for receiving
said compressed air and for delivering said compressed air to its said output means;
wherein all of said valve bodies' compressed air input means are in fluid communication
with each other; wherein one of said top and bottom plates further defines a compressed
air bore which receives said compressed air from said compressed air source and delivers
it to said compressed air input means of its said respective adjacent one of said
valve bodies; and wherein the other of said top and bottom plates comprises a plug
for an adjacent end of said compressed air input means of its said respective adjacent
one of said valve bodies.
14. The lubricator according to claim 12, wherein each said valve body's piston return
means comprises a spring located in a spring portion of its said piston chamber; wherein
each said valve body further comprises air relief means for providing air relief for
said spring portion of its said piston chamber; wherein all of said valve bodies'
air relief means are in fluid communication with each other; and wherein at least
one of said top and bottom plates defines an air relief bore which is in fluid communication
with said air relief means of its said respective adjacent one of said valve bodies.